* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Malgun Gothic", "Apple SD Gothic Neo", system-ui, sans-serif;
  color: #1f2328;
  background: #f6f8fa;
}
a { color: #0969da; text-decoration: none; }
a:hover { text-decoration: underline; }

.topbar {
  display: flex; justify-content: space-between; align-items: center;
  background: #24292f; color: #fff; padding: 0 20px; height: 52px;
}
.topbar nav a { color: #fff; margin-right: 18px; }
.topbar .brand { font-weight: 700; }
.topbar .userbox span { margin-right: 12px; color: #cdd3d9; }
.topbar .userbox a { color: #fff; }

.container { max-width: 1200px; margin: 24px auto; padding: 0 20px; }
h1 { font-size: 20px; margin: 0 0 16px; }
.muted { color: #6e7781; font-weight: 400; font-size: 13px; }
.error { color: #cf222e; }
.num { text-align: right; font-variant-numeric: tabular-nums; }

.filters { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 16px; }
.filters input, .filters select, .filters button {
  padding: 6px 10px; border: 1px solid #d0d7de; border-radius: 6px; font-size: 14px;
}
.filters input[type=text] { min-width: 260px; }
.filters button { background: #1f883d; color: #fff; border-color: #1f883d; cursor: pointer; }

table.grid { width: 100%; border-collapse: collapse; background: #fff;
  border: 1px solid #d0d7de; border-radius: 8px; overflow: hidden; }
table.grid th, table.grid td {
  padding: 8px 10px; border-bottom: 1px solid #eaeef2; font-size: 13px; text-align: left;
  vertical-align: top;
}
table.grid th { background: #f6f8fa; font-weight: 600; }
table.grid td.title { max-width: 380px; }

.grade { display: inline-block; padding: 1px 7px; border-radius: 10px; font-size: 12px; font-weight: 700; }
.grade-A { background: #ffebe9; color: #cf222e; }
.grade-B { background: #fff8c5; color: #9a6700; }
.grade-C { background: #eaeef2; color: #57606a; }

.pagination { margin: 16px 0; display: flex; gap: 14px; align-items: center; }

.login-wrap { max-width: 360px; margin: 80px auto; background: #fff;
  padding: 32px; border: 1px solid #d0d7de; border-radius: 10px; }
.login-form { display: flex; flex-direction: column; gap: 14px; margin-top: 16px; }
.login-form label { display: flex; flex-direction: column; gap: 6px; font-size: 14px; }
.login-form input { padding: 8px 10px; border: 1px solid #d0d7de; border-radius: 6px; }
.login-form button { padding: 9px; background: #1f883d; color: #fff; border: none;
  border-radius: 6px; font-size: 15px; cursor: pointer; }